well dude that will depend on the case really. not everyone had the same effects. but most ppl got some decent gains from CAI and full header and exhaust system. T-stat just keeps the engine running cooler to help with hp it doesnt really give you any extra. heads and intake are good for about 50+ cam maybe 30. depends ont he combo you run aswell. also remember that not all speed is in hp a CAI might not give you tons of extra power but it increases the response of the motor greatly and there for the over all feel and power.